The word Zelozelos is the Lenape word for cricket.
The word appears at the very end of Chapter 3. Half Arrow has brought True Son the "old worn bearskin that had been True Son's bed" at home with the Indian tribe. Half Arrow tells True Son that his father has sent him the skin, so that he "could go warm at night to (his) white people and remember (his) father," but True Son is concerned that now, Half Arrow, who has traveled far through the forest to bring him the gift, will have nothing to keep himself warm "on such a cold night." Half Arrow reassures True Son, telling him
"I have my strouding. Then I'll scrape myself a hill of leaves, yes a whole mountain to crawl inside of. I'll have a soft bed of leaves below me and a thick blanket of sweet-wmelling leaves above me. I'll bounce and flex my muscles till I sweat. Then I'll be snug and warm as Zelozelos, the cricket, in a wigwam."
The word Zelozelos appears to be derived from the sound a cricket makes; in this way, it is an example of onomatopoeia. The fact that it is capitalized indicates that Half Arrow is using the word familiarly, as a name for the cricket, who as part of the natural world is looked upon affectionately by the Lenni Lenape Indians.